Final answer:
The myelin sheath insulates axons and allows for saltatory conduction, leading to a much faster transmission of action potentials via the nodes of Ranvier, which ultimately makes neural communication more efficient and energy-saving.
Step-by-step explanation:
The myelin sheath plays a critical role in saltatory conduction, the process by which nerve impulses jump between the gaps in the myelin sheath known as nodes of Ranvier. Myelin acts as an insulator for the axon, which increases the speed at which action potentials are conducted. When an action potential reaches a node of Ranvier, it triggers the opening of voltage-gated Na+ and K+ channels, allowing Na+ to rush in and renew the depolarization process. This leads to the action potential 'jumping' from one node to the next, rather than having to regenerate continuously along the axon. This increases conduction velocity and makes neural communication more efficient and less energy-intensive.
Diseases like multiple sclerosis, which result in the loss of myelination, demonstrate the importance of myelin for proper nervous system function, as they lead to slowed conduction and various neurological deficits.